Ignition timing apparatus



IGNIT ION T IMING APPARATUS Filed Oct. 8, 1931 INVENTOR BY JOHN d EoaaPatented May 12, 1936 UNITED STATES PATENT OFFICE Application October 8,

24 Claims.

(Granted 1931, Serial No. 567,602 (Cl. 200-27) under the act of March 3,1883, as

amended April 30, 1928; 370 0. G. 757) The invention described hereinmay be manufactured and used by or for the Government for governmentalpurposes, without the payment to me of any royalty thereon.

5 The present invention relates generally to ignition timing apparatus,more particularly to improvements in circuit interrupters, or circuitbreakers as they are generally called, used for making and breaking anelectric circuit in the ignition system of an internal combustionengine; more specifically in structural character and operation thepresent invention has reference to and closely resembles in characterthat type of circuit breaker shown in my co-pending application SerialNo. 326,056, filed December 14, 1928, also my co-pendingjoint-application Serial No. 116,360, filed June 16, 1926, generallyreferred to therein as the pivotless breaker mechanism adapted forregulating and controlling the timing of the ignition circuit in aninternal combustion engine.

The primary object of the present invention is to provide in an electriccircuit breaker of the pivotless breaker type referred to hereinbefore,improved means for'supporting the fixed ends of the breaker contacts,making it substantially an integral molded unit construction to therebyeffect a more rigid and secure method of obtaining and maintainingcorrect alignment of the breaker contacts, providing a simplermechanism, positive and more effective in operation,

properly safeguarded whereby the same may against short circuiting bemanufactured at relatively small cost without sacrifice to quality and.I

35 whereby the mechanism may be easily assembled and readilydisassembled and renewals quickly and cheaply effected.

- A further object of the present invention is to provide a circuitbreaker of this" character, in which the movable contact arm of thebreaker mechanism is adapted to make line contact with the rubbing blockor cam follower at substantially the mid-portion of said contact arm soas to pre vent irregularities in the movement of the cam followerbrought about by uneven wear on the cam. follower or cam surface frombeing imparted to the movable contact arm. This improved constructionprevents torsional stresses being imparted to the movable contact armduring the make and break period and results in a clean instantaneousseparation of the contact points, eliminating substantially all therubbing action which might otherwise occur between the contact pointsduring the make and break perlodso that the efliciency of the currentcharge generated in the system will be maintained.

A further object of the present invention is to so mount a wick or otherequivalent lubricating means relative to a rotary cam or cam surfacethat 5 the wick or other lubricating means will be securely held inplace, said means being interposed I between the rotating cam andcontacts and forming a baflle so that lubricant thrown off from the camsurface by centrifugal action, which same might otherwise interfere withthe proper functioning of the contacts will be readily absorbed by thewicking material. a

A further object of the present invention is to provide in a breakermechanism of this character a rotating cam with suitable means which notonly prevent lubricant from accumulating in front of q the cam follower,but also efiects a uniform distribution of lubricant at all speeds tominimize wear.

The invention is further characterized byproviding a. breaker mechanismof this character in which the cam follower is interposed between thesupporting member of the breaking mechanism and the contacts so as themake and break period for a given'lift of cam follower. This feature isof particular importance in connection with battery ignition systemsbecause of the limited amount of lift that can be acquired on a batteryignition cam, which normally has a greater number of lobes than camsused in connection with magneto systems.

With these and other objects in view, the invention consists in thenovel features of con'struction and combination and arrangement of partsas will be more fully hereinafter described and pointed out in theclaims.

Referring to the accompanying drawing:

Fig. 1 is a plan view of an electric circuit interrupter in thepreferred embodiment of the present invention;

Fig. 2 is an enlarged top view partly in section of one of the contactassembly units shown in Fig. 1;

' Fig. 3 is an end view of Fig. 2 illustrating the 4 manner of attachingthe lubricating device to the assembly unit;

Fig. 4 is an enlarged detail plan view of the attaching device per se; I

Fig. 5- isa modification of the attaching means for the lubricatingdevice;

Fig. 6 is an end view of Fig. 5;

Fig. 'l is an end view of the cam for operating thecontact units; a I

Fig. 8 is a plan view thereof illustrating the arto give greater liftduring 25 I fixedly together and the surface taken .on the line Q--9blies II and. 5, which are attached to angled support members 8 and 9respectively. The plate I is provided with grooves I 0 and i Irespectively, within which snugly lit the two angled support members 8and 9. The plate I is also provided with a centrally disposed opening I2adapted to receive a shaft I3, upon which is mounted the four-lobed camB.

Each. contact assembly disposed on opposite sides of the cam 6 has itsvarious parts attached employed permit the parts of the assembly to bejointed together in a pivotless manner. The contact supporting member 8is provided with a rigid arm I4 which extends laterally away from theinner face I5 of the supporting member 8. Permanently attached at theend of the rigid arm I4 is a contact I6 and mounted. in permanentalignment therewith so that their relationship cannot be changed is asecond contact I1. The contact IT is permanently mounted on a flat leafspring I8 at a point lying substantially on the longitudinal axis ofsaid spring, the latter being supported at its other end by saidsupporting member 8. The inner end of said rigid arm I2 is provided withan opening I9 within which is disposed a fastening element 20 to whichthe leaf spring I8 heretofore mentioned is fastened. Molded to saidrigid arm I 4 and projecting through said opening I9 on either sidethereof is a spacer block 2| having a channel 22 formed on the upperside thereof within which the supported end of said leaf spring I8 isadapted to be snugly received.

The contacts I6 and I! are separated by means of a spring leaf timer arm23 of spring material provided at its free end with a rubbing block orcam follower member 24,.which is in continuous engagement with the camsurface of the cam 6 as will be noted by referring to Fig. 1 and inintermittent engagement with the free end of the spring I8 for movingthe movable contact I! away from the fixed contact I6 when the highpoints of the lobes of the rotating cam 8 are in contact with thefollower.

The supported end of said timer arm 23 is adapted to be secured to thelower end of the fastening element 28 heretofore mentioned, a channel 25being provided in the lower end of the molded spacer block 2| withinwhich the supported end of said timer arm is adapted to be snuglyreceived so that the timer arm together with the leaf spring I8 aremaintained in permanent fixed alignment with the rigid arm I4.

As will be noted by referring to Fig. 3, the free end of the leaf spring26 in lateral cross section is arcuate in shape with the center of theare lying within the leaf spring. It will also be noted that the upperor contacting surface 21 of the cam follower is flat so that in liftingthe leaf spring to efiect a ribbonlike fiat springs plane of symmetrya-a of the QJMO, 10d

separation of the contacts I 6 and II, physical contact between theupper contacting surface 21 of the cam follower and the arcuate portionof the leaf spring will be made along a line only, all points of whichwill lie within the plane of symmetry w-c of the leaf spring. Even.though the upper contacting surface of the cam follower is made arcuatein shape and the outer free end of the leaf spring 28 is made flat, orboth are made arcuate in shape with the arched portions disposed inopposing relationship, the same linear contact will be obtained withoutdeparting from the spirit of the invention. In this rnanner uneven wearof the cam follower will not impart any twisting action to the leafspring, torsional stresses occurring therein will be thus avoided and aclean and instantaneous breakaway of the con-- tacts will be effected.

In the present illustrated case, the rubbing block. or cam follower 24is made of an insulating material such as fiber, but when insulatingmaterial is not necessary other suitable materials may be used. Therubbing block is of such length as to provide a space 28 between it andthe end of the spring I 8 when the rubbing block is in engagement withthe low points of the lobes of the cam. Supported by the arm 23 andfixed adjacent the rubbing blocli 24 is provided a lubricating wick 29made of felt or other suitable absorb ent materials, the lower edge 38of which lies in substantially the same plane as the lower edge ill ofthe rubbing block so that there will be a physical contact or pressurebetween the wick and cam and such impact as may be imparted by the lobesof the cam will be taken up by the rubbing blocks.

In this manner a very thin film of oil will be continuously applied tothe cam surface of the cam b.

As will be noted by referring to Figs. 2, 3 and 4 respectively thelubricating wick 29 is mounted on the rearward wall 32 of the camfollower by means of a sheet metal clip 33 fixed to the rubbing bloclr21 by means of suitable rivets or the like 34. As will be noted the clip33 is provided on its outer edges with serrated teeth 35 adapted toengage with the absorbent material in the manner illusl trated in Fig. 3to substantially prevent any relative movement that may occur betweenthe wicking and cam follower when the circuit breaker is operated atcomparatively high speed.

In Figs. 5 and 6 are shown a modification of the lubricating wicking. Inthis modified form the wick 29 is first glued to the follower, therebypreventing substantially any relative movement between it and the camfollower. In addition to gluing the wick 29 to the cam follower, it isfurther secured to the same by means of a plurality of loops 36 and 31of silk strands or other suitable strong absorbent material tightlywound around the upper and lower portions of the rubbing block and wick,tying these loops together sewing through the wick to the upper loopsthereof, making several hitches to hold the loops together through thewicking. It will be further noted by reference to Fig. 6 that the lowerloops are secured above and below the timer arm. In this manner such oilas may accumulate on the face of the cam follower or at the juncture ofthe holding portion 38 and follower 24 by the scraping action of itsedge contacting with the cam 6, is prevented from flowing onto thefollower and the contacts I8 and I 1 due to the fact that the flowinglubricant is readily absorbed by the silk fibers and transmitted to thewick by capillary action. This method of hitching around the loops andthrough the wicking has the additional contacting portion of the wickingis in all cases.

equal to or greater than the width of the working face of the cam 6. Inthis manner the cam follower and wicking being interposed between thecam 6 and the end portion of the leaf spring l8 acts as a bafile whichprevents lubricant thrown from the cam in operating at high speed fromfouling the contacts I6 and H.

The cam 6 heretofore mentioned is further provided with a plurality ofgrooves 39 on the low points of the lobes, the purpose of which is toprevent lubricant from accumulating on the forward wall 40 of therubbing block by permitting spacer block having ing an a return flow ofthe lubricant to the wicking. The grooves, as will be noted by referringto Fig. 8, are staggered in relation to one another to distribute thewear evenly over the entire contacting surface of the cam.

In Fig. 10 is shown a modified form of the assembly units. In thismodified form the cam follower 24 is mounted on the timer arm 23intermediate the contacts l6 and I1 and their supported ends so as togive a greater lift during the make and break periods by increasing theeffective leverage.-

While I have shown my invention as applied to the electric circuitbreaker, it is not intended to limit myself to this type of device, nordo I intend to limit my invention to a liquid lubricant, since othertypes of lubricants may be used. Various devices are.provided with highspeed movable cams that require lubricating which may be effected by theapplication of my invention by making various slight changes in thegeneral form and arrangement of parts described without departing fromthe spirit of my invention.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. In an electric circuit breaker mechanism of the class described, arelatively stationary member carrying a contact, said memberhavlng anopening provided in the end thereof, a movable member carrying acooperating contact supported by said stationary member, and a spacerblock of insulating material molded to said stationary member andprojecting through said opening to form an integral unit adapted forspacing and insulating said movable contact carrying member from saidrelatively stationary member.

2. In an electric circuit breaker mechanism of the class described, arelatively stationary member carrying a contact, said member having anopening provided in the end thereof, a movable member carrying acoperating contact supported by said stationary member, and a spacerblock of insulating material molded to said stationary member andprojecting through said opening to form an integral unit adapted forspacing and insulating said movable contact carrying member from saidrelatively stationary member, said a channel molded therein adapted tosnugly receive the supported end of said movable member to maintain thecontacts in positively fixed relation.

3. In an electric circuit breaker mechanism of the class described, abracket having a relatively stationary arm carrying a contact, said armhavopening provided in the end thereof, a

fastening element disposed within said opening,

a movable arm carrying a cooperating contact positioned at the one endof said fastening element,

operative means for moving said movable contact arm positioned at theother end of said fastening element, and a spacer block of insulatingmaterial molded to said stationary member and extending through saidopening to surround said fastening element, said spacer block beingadapted for spacing said movable contactarm and operating means fromsaid stationary member, channels provided in the upper and lower endsrespectively of said spacer block, within which thesupported ends ofsaid movable contact arm and operative means are adapted to snugly fitto maintain the parts in positively fixed relation.

4. In an electric circuit breaker mechanism of the class described, amovable arm carrying a contact, cam actuated means for moving saidmovable arm, an L-shaped supporting bracket therefor having a relativelystationary arm carrying a contact interposed between said movable armand cam actuated means, a spacer block of insulating material molded tosaid stationary arm to form an integral unit therewith adapted forspacing and insulating said movable arm and cam actuated means from saidstationary arm, and a single fastening element for securing thesupported ends of said movable arm and cam actuated means to saidstationary arm.

5. In an electric-circuit breaker mechanism of the class described, abracket having a relatively stationary arm carrying a contact, said armhaving an opening provided in the supported end thereof, a spacer blockof insulating material molded to said stationary arm' and projectingthrough said opening, said spacer block being provided with a bore, afastening elementinserted in said bore, a movable arm carrying a contactpositioned at one end of said fastening element, cam actuated means formoving said movable arm positioned at the other end of said fasteningelement, said spacer block having a channel provided in the one endthereof adapted to snugly receive the fastened end of said movable armtherein to maintain its contact in positively fixed relation with thecontact on said relatively stationary arm.

6. In an electric circuit breaker mechanism of the class described, arelatively stationary arm carrying a contact, a movable member carryinga cooperating contact and a cam actuated member adapted for contactingsaid first mentioned member to separate said contacts, one of saidmembers having its contacting surface arcuate in shape, the center ofwhich l es within the plane of symmetry of said movable member tothereby obtain line contact between said members, all points of saidline lying within the plane of symmetry of said movable member.

'7. In an electric circuit breaker mechanism of the class described, arelatively stationary arm carrying a contact, a movable member carryinga cooperating contact, and a cam actuated member adapted to contact withthe free end of said movable member and substantially at themidlongitudinal portion of said movable member to separate saidcontacts, one of said members having its contacting surface arcuate inshape, the center of which lies within the plane of symmetry of saidmovable member to thereby obtain line contact between said members, allpoints of said line lying within the plane of symmetry of said movablemember.

8. In an electric circuit breaker mechanism of the class described, arelatively stationary arm carrying a contact, a movable member carryingacooperating contact, means for effecting make and break action of saidcontacts including a cam actuated member adapted to bear against thefree end portion of said movable member, one of said members having anarcuate surface for engaging the other member to make line contacttherewith substantially along the longitudinal axis of said movablemember.

9. In an electric circuit breaker mechanism of the class described, arelatively stationary arm carrying a contact, a movable arm of springmaterial carrying a cooperating contact in alignment with said firstmentioned contact, said movable arm having its free end portion curvedin cross-section, and means for eifecting make and break action of saidcontacts including a cam actuated member adapted to make line contactwith said curved portion, all points of said line lying within the planeof symmetry of said movable member.

10. In an electric circuit breaker mechanism of the class described, asupporting member, a relatively stationary arm carried by saidsupporting member provided with a contact, a movable arm of springmaterial carried by said supporting member and carrying a cooperatingcontact in permanent alignment with said first mentioned contact, thefree end portion of said movable arm being arcuate in cross section, andcam actuated member adapted to bear against the free end of said movablearm on a line lying substantially along the longitudinal axis of saidmovable arm to separate said contacts, said contacts being disposedintermediate of said cam actuated member and said supporting member.

11. In an electric circuit breaker mechanism of the class described, asupporting member, a relatively stationary arm carried by saidsupporting member and provided with a contact, a movable arm of springmaterial carrying a cooperating contact in alignment with said firstmentioned contact, a leaf spring timer arm carried by said supportingmember, and a cam actuated rubbing block on the free end of said timerarm adapted to bear against said movable arm on a line lyingsubstantially along the longitudinal axis of said movable arm toseparate said contacts.

12. In an electric circuit breaker mechanism of the class described, arelatively stationary member carrying a'contact, said member having anopening provided in the end thereof, a movable member carrying acooperating contact supported by said stationary member, a spacer blockof insulating material molded to said stationary member and projectingthrough said opening to form therewith an integral unit adapted forspacing and insulating said movable contact carrying member from saidrelatively stationary member, and cam actuated means adapted to contactwith said movable member at its free end at a point to separate saidcontacts.

13. In an electric circuit breaker mechanism of the class described, arelatively stationary member carrying a contact, said member having anopening provided in the end thereof, a movable member carrying acooperating contact supported by said stationary member, a spacer blockof insulating material molded to said stationary member and projectingthrough said opening to form therewith anintegral unit..adapted forspacing and insulating said movable contact carrying member from saidrelatively stationary member, and cam actuated means carried by saidrelatively stationary member comprising a rubbing block adapted tocontact with said movable member at its free end at a point lyingsubstantially along the longitudinal axis of said movable arm.

14. In an electric circuit breaker mechanism of the class described, a.bracket having a relatively stationary arm carrying a contact, said armhav ing an opening provided in the end thereof, a fastening elementdisposed within said opening, a movable arm carrying a cooperatingcontact positioned at the other end of said fastening element, and camactuated means carried by said relatively stationary arm comprising arubbing block adapted to contact with said movable arm at a point onlyto lift said movable arm and separate said contacts, said contacts beingdisposed between the point of lift and the supported end of said movablearm, the point of lift of said rubbing block lying substantially on thelongitudinal axis of said movable arm and coincident with the centerline of said contacts.

15. A unitary electric circuit breaker comprising in combination a pairof make and break contacts, means for supporting said contacts inpositive alignment including a relatively stationary arm carrying one ofsaid contacts, a leaf spring secured at its one endto said supportingmeans and having the other of said contacts mounted thereon, and meansengageable with said leaf spring adjacent said contacts for separatingsaid contacts, said last-mentioned means comprising a rubbing block thepoint of lift of which is maintained coincident with the center line ofsaid contact to prevent torsional stresses occurring in said leaf springduring the make and break period of said contacts.

16. In an electric circuit breaker mechanism of the class described, incombination a pair of make and break contacts, means for supporting saidcontacts in permanently fixed relation, a leaf spring secured at its oneend to said supporting means and having one of said contacts mountedthereon, a rotatable member having a cam surface, a rubbing blockactuated by said rotatable cam member and engaging thefree end of saidleaf spring adjacent its contact, and lubricating means carried by saidrubbing block for continuously lubricating said cam surface, said lastmentioned means being so constructed and arranged as to preventlubricant thrown from said rotatable member from strikin said leafspring.

17. In an electric circuit breaker mechanism of the class described, incombination a pair of make and break contacts, means for supporting Isaid contacts in permanently fixed relation, a leaf spring secured atits one end to said supporting means and having one of said contactsmounted thereon, a rotatable member having a cam surface, a rubbingblock actuated by said rotatable cam member and engaging the free end ofsaid leaf spring adjacent its contact, and lubricating means interposedbetween said rotatable member and the free end of said leaf spring andcarried by said rubbing block for continuously lubricating said camsurface, said lubricating means being so positioned as to preventlubricant from reaching said contact.

18. In an electric circuit breaker mechanism of the class described, incombination a pair of make and break contacts, means for supporting saidcontacts in permanently fixed relation, a leaf spring secured at its oneend to said supporting means and having one of said contacts mountedface, a rubbing block actuated by said rotatable cam member and engagingthe free end of said leaf spring adjacent its contact, and absorbentmaterial carried by said rubbing block for lubricating said cam surfacesupporting means, said absorbent material being so constructed andarranged as to readily absorb lubricant thrown from said cam surface tomaintain said contacts clean.

19. In an electric circuit breaker mechanism of the class described, incombination a pair of make and break contacts, means for supporting saidcontacts in permanently fixed relation, a leaf spring secured at its oneend to said supporting means and having one of said contacts mountedthereon, a rotatable member having a cam surface, a rubbing blockactuated by said rotatable cam member and engaging the free end of saidleaf spring adjacent its contact, and absorbent material for lubricatingsaid cam surface, supporting means for said absorbent material carriedby said rubbing block, the contacting portion of said absorbent materialbeing 'at least equal in width to the width of said cam surface toreadily absorb any lubricant thrown therefrom by centrifugal action.

20. In an electric circuit breaker mechanism of the class described, incombination a pair of make and break contacts, means for supporting saidcontacts in permanently fixed relation, a leaf spring secured at its oneend to said supporting means and having one of said contacts mountedthereon, a rotatable member having a cam surface, a rubbing blockactuated by said rotatable cam member and engaging the free end of saidleaf spring adjacent its contact, and absorbent material carried by saidrubbing block, the contacting portion of said absorbent material beinggreater in width than the width of said cam surface to form a battlewhich readily absorbs lubricant thrown from said cam surface bycentrifugal action.

21. In an electric circuit breaker mechanism of the class described, asupporting bracket including a relatively stationary arm carrying acontact, said supporting bracket being provided with an opening,insulation means disposed within said opening and secured to saidbracket to prevent relative angular movement between said bracket andsaid insulation means, and a.

movable contact carrying arm secured at one end to said insulationmeans.

22. In an electric circuit breaker mechanism of the class described, asupporting bracket including a relatively stationary arm carrying acontact, said supporting bracket being provided with an opening,insulation means disposed within said opening and secured to saidbracket to prevent relative angular movement between said bracket andsaid insulation means, said insulation means being formed withoppositely disposed parallel surfaces, a movable contact carrying armsecured at one end to the one surface of said insulation means andoperative means for moving said movable contact carrying arm secured atone end to the opposite surface of said insulation means.

23. In an electric circuit breaker mechanism of the class described, asupporting bracket including a relatively stationary arm carrying acontact, said supporting bracket being provided with an opening,insulation means disposed within said opening and secured to saidbracket to prevent relative angular movement between said bracket andsaid insulation means, said insulation means being formed withoppositely disposed parallel surfaces, a movable contact carrying armsecured at one end to the one surface of said insulation means andoperative means for moving said movable contact carrying arm secured atone end to the opposite surface of said insulation means, saidinsulation means being provided with a recess on one of said surfacesadapted for receiving the supported end of said movable contact carryingarm therein to maintain the contacts on said stationary arm and movablearm in fixed relationship.

24. In an electric circuit breaker mechanism of the class described, asupporting bracket including a relatively stationary arm carrying ,acontact, said supporting bracket being provided with an opening,insulation means forming a spacer block disposed within said opening andfixedly secured to said bracket to prevent relative angular movementbetween said bracket and said insulation means, said insulation meansbeing formed with oppositely disposed parallel surfaces, a movablecontact carrying arm secured at one end to the one surface of saidinsulation means, operative means for moving said movable contactcarrying arm secured at its one end to the opposite surface of saidinsulation means, the said. surfaces of said insulation means beingprovided with oppositely disposed recesses adapted to snugly receive thesupported ends of said operative means and movable contact carrying armstherein to prevent relative lateral or angular movement between thesupported ends of said movable contact carrying arm, said operativemeans and said stationary arm.

JOHN J. ROSE.

